<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div style="height: 70px;border: blue 10px dashed">
        <div class="c1" style="height: 20px;border: red 4px solid"></div>
    </div>
    <div style="width: 500px;background-color: #00b0e8">
        <div style="width: 20%;background-color: red;float: left">1</div>
        <div style="width: 70%;background-color: black;color: white;float: left">2</div>
        <div style="clear: both"></div><!--放在最后-->
    </div>
</body>
</html>